Voters in the 12 states USA Today and Gallup consider the key swing states that could decide the 2012 presidential election are now significantly more enthusiastic about voting this fall than they were in June. Six in 10 (59%) are either "extremely" or "very" enthusiastic, up from 46%.

Voter enthusiasm in these states has grown among members of both political parties; however, Democrats' level has increased more. Thus, whereas equal percentages of Democrats and Republicans were enthusiastic in June, Democrats are now significantly more enthusiastic than Republicans, 73% vs. 64%.

Independents' enthusiasm also jumped substantially over this period -- up 18 points, similar to the 20-point gain among Democrats; however, independents' enthusiasm still lags behind that of both partisan groups.

Gallup finds a similar pattern among voters nationwide. Overall, 55% of U.S. registered voters in the latest poll are either extremely or very enthusiastic about voting in this fall's election, up from 43% in June. This includes a 19-percentage-point increase among Democrats and roughly 10-point increases among independents and Republicans.